Home Energy and Environment Solid Aftershock Shakes Central Virginia in Wake of August Earthquake

Solid Aftershock Shakes Central Virginia in Wake of August Earthquake

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Up until last August, tonight’s 3.2 earthquake in central Virginia would have been big news. But in the wake of August’s 5.8 quake that shook much of the East Coast, the steady stream of light tremors in & around Louisa since then haven’t gotten much attention. More on tonight’s temblor from WTVR’s Zach Daniel:

A magnitude 3.2 aftershock occurred at 6:39 PM this evening 5 miles south of Louisa and was felt across much of central Virginia. This aftershock was one of the strongest since the original quake back in August. I’ve been getting a lot of questions on my facebook page about these aftershocks, and specifically when we can call them a new earthquake. Technically, all of these aftershocks are earthquakes, but we call them aftershocks because they are smaller earthquakes associated with the larger seismic event (the 5.8 magnitude quake). If an aftershock is stronger than the original earthquake, it will be deemed the main quake, and all subsequent seismic activity will be referred to as foreshocks. Here’s hoping tonight’s was the last of them, but I doubt it.

While the U.S. Geological Survey has linked natural gas fracking to recent earthquakes in Youngstown, OH, talk linking fracking to Virginia’s quake has been more speculative. Did you feel tonight’s quake?

  • Dave

    …is just an earthquake.

  • hopeful monster

    Saying that fracking links to Virginia’s earthquakes are “more speculative” is like saying “discussion that President Obama was born in Kenya is more speculative.”

    The only speculation that I’m aware of is the single DailyKos diary you linked to, which bordered on conspiracy theory (with its Google Earth images of supposed secret fracking sites). Certainly I’m unaware of any geologists “speculating” about a fracking link to the Virginia earthquakes. In fact, in the comments section of the diary you linked to there were several comments from geologists (including me) explaining in some detail why there was no reason to suspect fracking in this instance. It’s called the Central Virginia Seismic Zone for a reason; there’s abundant evidence for seismic activity in the Virginia Piedmont and Coastal Plain going back at least 50 million years, and probably going back more than 200 million years.

    Fracking can cause earthquakes in some settings, as the USGS has shown in the link you provided. Much more significantly, it can cause all kinds of groundwater problems that can result in a cascade of environmental issues, and is probably a practice that should be stopped entirely, or at least restricted to certain geologic settings under tight regulation. But pointing to made-up connections (like the VA earthquakes) does nothing except hurt the credibility of fracking opponents.